Author
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Mitchell, Andrew |
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Submitted to: North American Journal of Aquaculture
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/30/2004 Publication Date: 1/1/2005 Citation: Mitchell, A.J. 2005. A simple assay to compare zeolite ammonia control properties. North American Journal of Aquaculture. 67:18-22. Interpretive Summary: Fish produce ammonia and excrete it into the water and unless it is removed it can reach concentrations lethal to the fish. In fish shipment containers, zeolites are often added to reduce ammonia levels that build up after several hours. Zeolites purchased from aquaculture industry suppliers vary in quality and little information is provided about the origin, type, and purity of the zeolites. The only way to determine the suitability of these products is through evaluations of their ability to remove ammonia. A simplified method for comparing the ammonia removal potential of zeolites was developed for use by fishery extension specialists and by fish producers equipped with some basic scientific equipment. This method incorporates simple water tests kits used by fish producers and methodology and equipment that could be readily used and purchased by fish producers. It allows a producer or fisheries extension worker to easily and quickly (within about 45 min) compare several zeolites to determine which one to chose for use in shipping containers. Technical Abstract: Zeolite is often placed in fish shipping containers to reduce the ammonia concentration and increase fish carrying capacity. Zeolites purchased from aquaculture industry suppliers vary in quality and little information is provided about the origin, type, and purity of the zeolites. The only way to determine the suitability of these products is through evaluations of their ability to remove ammonia. A simplified method for comparing the ammonia control properties of zeolites was developed for use by fishery extension specialists and by fish producers equipped with some basic scientific equipment. This comparative evaluation of zeolites was accomplished using inexpensive total ammonia nitrogen test kits. Ammonium sulfate (0.1 g) was dissolved in 1 L distilled or de-ionized water and zeolite (10 g) was added to the solution and stirred for 20 min. Aliquots of water from each test were diluted 1:6 and the ammonia concentration measured. Five zeolites with varying ammonia removal capacities were tested and it was shown that all could be compared effectively with two different ammonia test kits using the same procedure. |
